In order to visually represent a feature and a tendency of numerical data, in general, a graph displaying device is widely used. In the graph displaying device, a graph is created based on the numerical data, and the graph is displayed on a display screen. In this case, a user can variously indicate a range of the numerical data and a shape of a graph used for creating the graph.
Furthermore, recently, in various technical regions, research and development is performed by putting big data to practical use. In this practical use of big data, graph-creating by analyzing the numerical data is extremely important, and widely desired.
A data amount handled by processing the big data is enormous. Accordingly, when a graph based on the numerical data is displayed, the user often wants to indicate a segment of specific numerical data, in order to display a graph in the segment.
However, in the segment of numerical values to be displayed as a graph, if a value (outlier) largely shifted from other values is included, the user cannot understand variation of graph of the other values (except for the outlier). Namely, it is hard for the user to view the graph.